Dental crown-slitting tool.



Patented Apr. 1; F902; a. w. TEUFEL. DENTAL GROWN SLITTING TOOL.

(Application filed Nov. 25, 1901.)

(N0 Model.)

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GEORGE \V. TEUFEL'OF PHILADELPHIA, PENNSYLVANIA.

DENTAL CROWN-SLITTING TOOL.

SPEGIFEGATION forming part of Letters Patent No. 696,772, dated April 1,1902. Application filed November 25, 1901. Serial No. 83,493. (Nomodel.)

To all whom it may concern:

Be it known that I, GEORGE W. TEUFEL, a citizen of the United States,residing at the city of Philadelphia, in the county of Philadelphia andState of Pennsylvania, have invented certain new and useful Improvementsin Dental Grown-Slitting Tools, of which the following is aspecification.

My invention has relation to a dental tool adapted for slitting andremoving cap-crowns from teeth; and in such connection it relates to theconstruction and arrangement of such a tool.

The principal object of my invention is to provide a crown-slitting toolof improved construction which shall be efficient in operation andrelatively simple and inexpensive to make.

The nature and scope of my invention will be more fullyunderstood fromthe following description, taken in connection with the accompanyingdrawings, forming part hereof, in which- Figure 1 is aside elevationalView of a crown-slitting tool embodying main features of my invention.Fig. 2 is a front elevational view of the same. Fig. 3 is a sectionalview, enlarged,illustratin g the construction and arrangement of theknife of the tool. Fig. 4 is a similar view of the jaw bearing upon thecrown of the tooth, and Figs. 5 and 6 are detail views of the pivotalconnection between the two arms or levers of the tool.

Referring to the drawings, ct and b represent the two arms or levers ofthe tool. The arm Ct carries at one end the slitting jaw or beak A,constructed and arranged as follows:

The arm a is enlarged into a ring or sleeve a,

the bore a of which is conical. A stud a provided on its periphery witha knife a has a stem a, which enters the bore a of the sleeve 0; and isupset thereon to prevent the stud a from being disconnected from thesleeve. The connection of the stud a with the sleeve a is sufficientlyloose to permit the stud a and knife a to turn in the sleeve a,whileclamping the inner face of the stud (1 down upon the outer face ofthe ring a. The position of the knife a may therefore be readilychanged, so that in operation it may slit the crown of the tooth on anyline along its periphery. The knife-edge projects radi ally from thestud a and extends beyond the periphery of the adjacent ring a, in whichthe stud and knife turn. The other arm I) is provided with a bearing jawor beak B, constructed and arranged as follows: The end of the arm, hisenlarged into a cup I), the rim or perimeter of which is annularlygrooved, as at 17 This'cup fits down upon the cuspid surface of thetooth, and the ridges of the groove Z2 tightly fit upon the crown toprevent the jaw or beak B from slipping off of the crown when the toolis used. The hollow b of the cup b is of a diameter sufficient to permitof the sleeve a, stud a and knife a entering the hollow of said cup 5,the top or point of the knife, however, being in substantial alinementwith the inner ridge of the groove 79 In tools of this character it isdesirable that the two arms be readily separable, so that the pivot orjoint can be washed with an antiseptic substance. One way of makingthese arms a and b separable is illustrated in the drawings. At thepivotal point of the arms each arm a or b is enlarged into a block a orI), having its upper and-lower curved edges a or b tapered or beveled.This block a or b engages a complemental recess 19 or a in the otherarm. When the two arms a and b are turned to the position illustrated inFig. 5, the beveled edges a and 5 clear the complemental recesses 23 ora and the two arms may be separated. One arm a or Z) carries thepivot-pin a", and the other arm I) or a is perforated, as at 6 toreceive the pin.

In operation the two jawsof the tool are separated and the cup I) isfitted down upon the crown of the tooth. The two jaws are then broughttogether to bring the knife down upon the side of the tooth, While stillmaintaining the grooved cup upon the crown. The knife then cuts into theside of the tooth as the knife-jaw approaches the bearing-jaw, and theside of the tooth is thus slit from the root toward the crown.

Having thus described the nature and objects of my invention, what Iclaim as new, and desire to secure by Letters Patent, is-

1. In a dental tool for slitting cap-crowns, aslitting-jaw comprising anarm, the free end of which is enlarged into a ring, a stud having aninner face resting upon the outer face of said ring, a stem projectingfrom the stud and entering the center of the ring to form a swivelconnection between the stud and ring and a knife projecting radiallyfrom the periphery of the stud and having its point projecting beyondthe periphery of the ring, and a bearing-jaw cooperating with theslittingaw.

2. In a dental tool for slitting cap-crowns, a bearing-jaw comprising anarm, the free end of which is enlarged into a cup, said cup having itsrim ridged to form an annular groove concentric with the interior of thecup, in combination with a slitting-jaw comprising an arm having itsfree end enlarged into a ring of a diameter less than the diameter ofthe cup,

a stud having an inner face resting upon the outer face of the ring, astem projecting from the stud and fitting the center of the ring to forma swivel connection between the stud and ring, and a knife projectingradially from the periphery of the stud and having a point projectingbeyond the periphery of the ring and in alinement with the inner ridgeof the cup in the bearing-jaw.

In testimony whereof I have hereunto set my signature in the presence oftwo subscribing witnesses.

GEO. W. TEUFEL.

Witnesses:

J. WALTER DOUGLASS, THOMAS M. SMITH.

